The present invention relates to the general field of nacelles fitted to turbojets.
A turbojet nacelle generally comprises an upstream air intake structure for channeling the stream of air towards the turbojet fan, a middle structure that is fastened to the air intake structure and that serves to surround the turbojet fan, and a downstream structure giving access to the central portion of the turbojet and housing a thrust reverser system.
Maintenance operations on a turbojet fitted with such a nacelle require manufacturers to provide access hatches in the nacelle. In particular, it is common practice for the middle structure of the nacelle to be fitted with semicylindrical covers that are hinged about longitudinal axes in order to provide access to the turbojet while maintenance operations are performed thereon.
Nevertheless, the presence of covers has the harmful consequences of increasing the drag of the nacelle and of increasing its weight. In order to mitigate those drawbacks, proposals have been made for a portion of the air intake structure of the nacelle to be removable. That solution gives easy access to the turbojet during maintenance. Reference may be made in particular to patent application FR 2 906 568, which describes an embodiment of a nacelle having a removable air intake structure. By eliminating the covers, the drag and the weight of the nacelle are reduced.
That type of nacelle having a removable air intake structure nevertheless raises a problem at the junction between the portion of the structure that can be removed and the portion that remains stationary. When the nacelle is in the closed position, the presence of clearance between those two elements gives rise to aerodynamic disturbances that harm the performance of the turbojet and give rise to leaks of air into the compartment of the air intake structure.
In order to minimize that clearance, proposals have been made to fill it with a gasket or to make provision for the stationary and removable portions of the air intake structure to overlap in part when the nacelle is in the closed position. Such arrangements are nevertheless not fully satisfactory since they continue to give rise to aerodynamic disturbances in operation.